Fluorine containing polymers and coating compositions prepared therefrom

Abstract

A fluorine containing polymer containing ester groups in the backbone of the polymer is prepared by the ring opening free radical polymerization of a cyclic ketene acetal with a vinyl monomer component comprising a fluorine containing vinyl monomer. The aforesaid fluorine containing polymer which contains ester groups can be reacted with a material containing functional groups capable of cleaving the carbon oxygen single bonds of the ester groups. The resultant oligomeric material contains functionality as a result of the cleavage which is suitable for reaction with a crosslinking agent to form a cured film.

What is claimed is: 
     
       1. A fluorine containing polymer containing ester groups in the backbone of the polymer which is prepared by the ring opening free radical polymerization of a cyclic ketene acetal with a vinyl monomer component comprising a fluorine containing vinyl monomer. 
     
     
       2. The polymer of claim 1 wherein the ester groups are distributed in the backbone of the polymer in a substantially random manner. 
     
     
       3. The polymer of claim 1 wherein there are present in the vinyl monomer component in addition to the fluorine containing vinyl monomer other polymerizable vinyl monomers. 
     
     
       4. The polymer of claim 1 wherein the cyclic ketene acetal is represented by the following structural formula: ##STR2## wherein n is an integer of at least 2; R' and R are independently selected from hydrogen, lower alkyl, halogen or lower alkoxy.   
     
     
       5. The polymer of claim 4 wherein the cyclic ketene acetal is 2-methylene-1,3-dioxepane. 
     
     
       6. The polymer of claim 1 wherein the fluorine containing vinyl monomer is selected from 1,1-difluoroethylene, 1,2-difluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, vinyl fluoride and perfluorohexylethylene. 
     
     
       7. The polymer of claim 1 wherein the ring opening free radical polymerization is conducted with a peroxide initiator. 
     
     
       8. The polymer of claim 4 wherein the lower alkyl is a C 1  to C 4  linear alkyl. 
     
     
       9. The polymer of claim 4 wherein the lower alkoxy group is represented by OR" wherein R" is C 1  to C 4  linear alkyl.